Based on the summarizing of the development history of the migrant workers' social security system and contrasting with the urban citizens,this paper analyses current situation,existing problems and reasons of the migrant workers' social security system of the migrant workers.This paper also analyses the influence of Social Insurance Law,and explores the future direction of the migrant worker' social security system.At last,this paper puts forward some policy recommendations such as building social assistance system of the migrant workers,promoting the overall level,encouraging the labor union organization to play an important role in safeguarding rights,enhancing the training of the migrant workers,increasing the financial investment on education of the children of the migrant workers,resolving the short supply of public rental housing through multiple channels etc. <<